## Tesla’s big electric truck faces an even bigger infrastructure challenge The 500-mile Semi arrives as charging gaps still limit electric trucking. Tesla CEO Elon Musk has insisted investors think of his electric automaker as a robotics and autonomous vehicle company now. He’s targeted a $20 trillion valuation—nearly four times the value of market leader Nvidia—on that premise. But his Tesla team was in Sparks, Nevada, on Thursday to focus on, well, an electric vehicle: the long-awaited Tesla Semi. The Semi concept first rolled onto a Tesla event stage in late 2017. Nearly a decade later,…